be in bed with
To be in a relationship with another person, either for business or pleasure, and often with an air of unseemliness. I don't trust Albert because I heard he's in bed with the mob. Did you hear that Todd was in bed with his secretary? How gauche.
be in bed with somebody/something,
get into bed with somebody/something (disapproving) if two people or organizations are in bed with each other, they have a close relationship and help each other: They claim that he is in bed with terrorist organizations. ♢ Investors are wary of getting into bed with an industry often tied to gangsters.